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Oct 20, 2015

After a storm: if you lost power, check for unseen problems at your industrial facility that could cost you

It's easy to tell at home when the power has been shut off: digital clocks may blink or be showing the wrong time. But at an industrial facility, equipment that seems to function normally after a power outage could be running inefficiently if control systems automatically switch to default settings.

Specialized equipment may lose optimal settings – and benefits – when power returns

In late August, the Lower Mainland and parts of Vancouver Island experienced a sudden, intense wind storm, causing the largest power outage ever experienced in BC Hydro's history.

Power was restored rapidly; fallen trees and branches were hauled away. And things generally appeared to go back to normal.

However, appearances can be deceiving. If you're an industrial company that relies on specialized electric and electronic equipment, you could face hidden costs after a power outage.

Know what to look for to prevent hidden costs

David Rogers, an engineer at BC Hydro, paints the picture.

"In your home, when the power goes out, you'll see the clocks on your stove and microwave flashing, and you have to reset them," he says. "In a factory, there are dozens of clocks and control systems, and even motors that can be turned off or burned out. You wouldn't necessarily know you have these problems. You need to establish a routine to check for them."

With 21 years of experience visiting industrial sites for BC Hydro, Rogers says being prepared for the aftermath of an outage is worth it. "I've seen people who have lost a lot of money as a result of not knowing what to do after there's been a power outage."

Control systems: After an outage, the customized settings on electronic control systems may be lost as the system reverts to a default setting. That means it could continue to function – but not with the configuration that's optimized for your operation.

Variable frequency drives (VFDs): Used on many types of equipment, these respond to work loads and ramp up or down as required, saving energy by "right-sizing" the equipment's response. A power outage may cause them to reset to a single speed, negating potential energy savings.

Relay switches: These electro-mechanical switches carry messages from the computer brain of a control system out to the actual equipment being controlled. Because they operate in a low voltage system, the upset of an outage and possible subsequent power surge can cause them to heat, fuse, and fail. "The computer system won't know, and will think everything is fine," says Rogers. Meanwhile, systems may not function as planned.

Quality control: Often quality is checked by electronic equipment. Rogers offers the example of a resin manufacturer with a control system that checks products for difficult-to-spot impurities. "If the system is not optimized, you might wind up discarding 5-6% of your product due to impurities, rather than your normal 2%."

Waste: After an outage, a system that manages an input such as water might fail to respond to varying needs. "For example, you might be pumping water through a system that doesn't need water at the time, so it's going straight down the drain – and many businesses pay for water," says Rogers.

Equipment overload: Power lines typically have three "phases" or wires. An outage can short out one wire, leaving the remaining two carrying the full current load. This can affect equipment such as motors, causing them to burn out due to high inrush currents.

IT infrastructure: Industry is relying more and more on adequately performing IT (information technology) assets. Power outages typically impact IT hardware by taking out the weakest links, such as older switches. Software scheduling and many other applications can collapse or fail to work properly.

Rogers says problems don't automatically occur after an outage; equipment may reset itself accurately and there may be no harm done. But he says it's important to ensure that employees watch for anomalies after an outage.

"For example, if they start to see a lot more waste, or they notice that power usage is up, or they're wondering, ‘Why did we use 10% more water last month?'" he says. "People wouldn't necessarily associate those changes to a power outage. The situation could go on for months, and they might just shrug their shoulders and think, ‘Well that's weird.'"

Create a governance structure for an after-outage checkup

Rogers suggests that companies could develop a checklist of systems that use sensitive equipment such as controls, VFDs, or relay switches that should be assessed after an outage. Most importantly, he says, there needs to be someone accountable for the follow-up routine.

"You know, most plants are so busy, no one is empowered with this," he says. "There's no governance to put someone in a position to be aware after a power outage that things can change, and problems can occur. It needs to be someone's job."

Rogers suggests that three areas share responsibility for the post-outage check-up: maintenance, software and quality control. Between them, they should tour the plant and check for problems, and remind employees to be on the lookout for anything that isn't running as it was before. He says the group should report through to a single manager who would determine if any action is needed.

"This isn't to say that after a power outage all these problems will occur," says Rogers. "But there is a possibility, and it can be costly. In the real world, stuff happens – and it's best to be prepared."

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